平流层飞艇绕流场与柔性变形的数值模拟

Coupling Computation of Ambient Flow and Deformation of Elastic Membrane Body

处于平流层流场中的飞艇,其整体刚度较小,为柔性体,可视为弹性薄膜结构,外围的流场的状态分布与其形状有着密切的关系,从本质上说是一个流固耦合问题。本论文以此为背景,分析了平流层飞艇的外围流场与柔性蒙皮变形的非动态耦合关系。我们采用叠代计算方法来处理这一问题,其中飞艇的三维流场的计算本文采用基于有限体积法的压力修正SIMPLE算法,而飞艇弹性变形的数值模拟计算应用了薄壳无矩理论。本文比较了气动弹性变形和静态超压变形两种不同情况下的飞艇流场压力分布以及气动参数,分析了飞艇变形与流动参数、气动荷载变化的关系。

The airship placed in the stratosphere flow field is a flexible body with low rigidity and so can be taken as an elastic membrane structure. The distribution of the peripheral flow field aroung the airship is closely related to its shape. It is essentially one of the Fluid Structure Interaction （FSI） problems. Based on this, this thesis focuses on the non-dynamic coupling of the peripheral flow field of the airship in the stratosphere and its deformation. For the solution of this problem, the iteration method was introduced, and the three-dimensional flow around the airship was studied numerically by means of SIMPLE method based on the Finite Volume Method. In the numerical simulation of the elastic deformation, the moment theory of thin shell was introduced. A comparison between the pressure distribution and aerodynamic parameters was provided, when the aeroelastic deformation was considered for static overpressure body. The relations between the deformation and the changes of flow parameters and pneumatic loads were also analyzed.